How can I get operating the code vector computing with different size matrix

I want to do vector operations.

When the initial position x = s, 1000 particles enter the function with different phases, they receive different E-fields through a while loop and reach the point x = 0. This will cause the loop to end at different points, causing an error.

I am wondering how to solve this problem.

Answer 1

[KSSV]

Read about logical indexing. Pick the points or x which are not zeros and do the operations on only those points ignoring the points which have value zero or attained zero.

Some think like shown:

idx = x > 0 ;
x_nonzeros = x(idx) ; 
% do the operations on x_nonzeros
x(idx) = x_nonzeros   % fill the obtained value back in x at the indices 

[inho seong]

Thanks for your reply.

Thanks to your comment, I could solve my problem vecterized.